Sealing devices for rotary piston machines

ABSTRACT

A sealing device for rotary piston machines of the type having radial segments fitted into cavities in the stator, characterized in that this device is comprised of a detachable assembly formed by a segment holder support, a lateral shim, a radial segment and their resilient bearing means, said assembly being fitted into a corresponding cylindrically-walled cavity provided in the stator and a lateral cheek, said assembly coming into resilient bearing contact against a lateral sealing shim situated in the opposite cheek, an exterior thrust washer ensuring that this assembly is maintained in resilient juxtaposition with the radial segment and of the lateral sealing shims.

United States Patent 1191 Brille 1451 Sept. 18,1973

[54/] fif gg gm FOR ROTARY N FOREIGN PATENTS OR APPLICATIONS 997,8147/1965 Great Britain l23/8.0l [75] Inventor: Maurice G. Brille,Billancourt,

France a Primary ExaminerCarlton R. Croyle [73] Assignee: RegleNationale Des Usines Renault, Assistant vExfmmend:hard Gluck Binancourtprance Attorney-Richard K. Stevens et a1.

[22] Filedz. Dec. 27, 1971 [57] ABSTRACT [21] Appl' 212,176 A sealingdevicefor rotary piston machines of the type having radial segmentsfitted into cavities in the stator, [30] Foreign Application Priorit 1)characterized in that this device is comprised of a de- Jan 5 1971France 7100086 tachable assembly formed by a segment holder support, 7

a lateral/shim, a radial segment and their resilient bear- [521 LS. Cl.I I i ll'lg means, said assembly being fitted into a corre- [511 Inc.01...... i 01; 19/02 F64c 15/00 slmding cylindricauy'waued cavity Pmimd[58] Field oi p 1 67 128 stator and a lateral cheek, said assemblycoming into t 6 21 resilient bearing contact against a lateral sealingshim i situated in the opposite cheek, an exterior thrust [56] ReerencesCited washer ensuring that this assembly is maintained in resilientjuxtaposition with the radial segment and of the UNITED STATES PATENTS IV lateral sealing shims. 3,326,455 6/1967 Kell 123/801 x 3,369,7392/1968 Abermeth 418/129 x 10 Claims, 4 Drawmg Figures 27 Z0 18 1 6 1 5 a1 g 25 v 6 J 9 17 n W//////// 23 11- 4 24 8 T m 3 4 g 20 I g l SEALINGDEVICES FOR ROTARY PISTON MACHINES This invention relates to a sealingdevice for rotary piston machines, whose rotor or rotary pistoncomprises a peripheral profile with epicyclic lobes rotating in a statorof conjugate profile comprising an additional lobe.

In these appliances radial sealing segments are usually arranged to joinup with the stator lobes, each lobe thus forming a combustion orcompression chamber according to whether it is a case of an engine or acompressor.

These segments are generally completed by radial sealing segments.Lateral sealing shims ensure continuity of sealing between radialsegments and lateral segments. All these sealing elements have theadvantage of being mounted in the stator and of being fixed.

The object of the present invention is to derive the utmost benefit fromthis advantage with an arrangement which enables quick and easy changingof each segment, this changing being able to take place, if necessary,without stopping the machine, the latter continuing to rotate with thetwo lobes adjacent to the segment to be changed being put out ofoperation.

Another objectof the invention is to be able to adjust, duringoperation, the directional setting of the radial segment.

In fact it is advantageous to be able to carry out, during operation, anadjustment of the inclination of the radial segments as a function ofvarious parameters, such as rate of flow, amount of leakage, power'oreffis ciency, the adjustment of this setting angle being likewise veryimportant for preventing identations on the rotor surface.

For this purpose the device forming the subject matter of this inventionis characterised by a cylindrical support angularly adjustable about itsaxis and comprising at one end a seating collar for accornodating alateral sealing shim, whose outer face constitutes a closure bearingface,-and whose opposite face is extended over the full width of therotor by a cylindrical shaped element truncated longitudinallysubstantially along a sector of its section and of the same outerdiameter as the collar, a slot situated in the axial plane of saidshaped element receiving a sealing segment whose contact profile, whichis substantially cylindrical, has as pivot axis the same axis as thecylindrical outer bearing surface of the segment support formed by saidcollar and said shaped element.

The assembly formed by the segment support, the lateral shim, the radialsegment, their resilient bearing means and the means for the angularsetting of the seg ment is fitted into a correspondingcylindrically-walled cavity provided in the stator and a lateral-cheek,said assembly coming into resilient bearing contact against a lateralsealing shim situated in the opposite cheek. An exterior thrust washersupporting the control means for the angular adjustment of thesegment-holder assembly ensures that this assembly is maintained inresilient juxtaposition with the segment and with the lateral sealingshims. g

Another object of the invention is to allow the dismantling of adefective assembly and the putting into position of a new assemblywithout the machine having to be stopped. For this purpose thecylindrical portion in the stator and the lateral cheek comprises alongitudinal dovetailed slot with which an equivalent slot in theoscillating support registers in the mean position.

After dismounting the closure washer from the assembly the latter issimply withdrawn, nothing opposing its long'tudinal sliding. The angularadjustment members ensure a convenient @ip on the assembly so as toeffect this removal. On reassembly a guide fillet with a double dovetailis inserted into the corresponding slot of the cheek and of the statorand a new assembly, guided by its own slot into the lower dovetail ofsaid fillet, is sunk into the seating.

For the purpose of preventing premature contact between segments, guidesand rotor, thus risking damage to their surfaces, the radial segment iskept sunk in at maximum clearance of the space swept by the surface ofthe rotor in its seating by means of beads of lowrnelting pointmaterial, such as wax, which are removed without residues and sunk intodrilled holes having their axis on the lateral surface of contact of thesegment with the corresponding surface of their seating in the support.

After the complete insertion of the assembly the guide fillet iswithdrawn and the closure washer replaced. The gradual rise intemperature of the assembly due to contact of hot components of themachine causes melting of the wax plugs and the gradual release oftheresilient means due to longitudinal shearing of the wax plugs in apasty state and the putting into operational contact of segment with thesurface of the rotor.

Such a device while remaining relatively simple in production allowsgreat possibilities in adjustment and renders the replacement of worncomponents as a routine operation, even in extreme cases of changingwithout' stopping the machine. These extreme cases can arise in marinemachines or in any industrial installation which must ensure continuousservice without failure. I

The simple shapes of the shims, guides and segments allow them to beproduced economically from fritted porous self-lubricating materials.

One embodiment of the device according to the invention appears ingreaterdetail in the following description and drawings, in which:

FIG. 1 is a view in axial section along the line II (FIG. 3) of asegment holder assembly in accordance with the invention mounted on themachine.

FIG. 2 is an end view of the same assembly showing the control membersfor adjusting the angular setting of the segment holder.

FIG. 3 is a section along the line III-III (FIG. 1) of a segment holderassembly in operation,

FIG. 4 is a section similar to FIG. 3 of a segment holder in the courseof being mounted on a machine in operation.

Referring to thedrawings, in FIG. 1 the segment holder support 1 ismounted in the seating of a stator 2 in which a rotor 3 rotates. On thissupport there'is mounted a radial sealing segment 4 bearing in an axialslot against pressure springs 5 (these springs could if necessary be ofthe same type as those used in french Patent No. 1,431,008 in theApplicants name) and there is also mounted a lateral sealing shim 6 withits pressure springs 7 and its screwed-in support cover 8.

A screwed-in plate 9 fitted into the end of the support 1 ensures thatthe segment 4 is held in position during the mounting operations.

For this mounting operation there is likewise provided a dovetaileddouble guide slot 16 in which a guide bead 17 engages (FIG. 4).

The means for adjusting the inclination setting of the segment holderassembly 1 comprise a connecting sembly, after adjustment of theinclination of the segment holder assembly, on a bearing and lockingwasher 18.

The control of the adjustment of this inclination is ensured by a screw25 operated by a knurled knob 28 and mounted freely rotatably in a boss29, likewise mounted freely rotatably in the bearing washer 18 inaccordance with the same arrangement as the boss 14 in the component 10.

This arrangement offers the advantage of an adjusting and locking devicewhich forms a self-contained unit not requiring any special machining tothe main components such as the cheek l9 and the stator, except for thethreaded holes for fastening the screws 20. It likewise remains simplein production and with minimal space requirements.

The segment holder assembly is kept in its seating by the bearing washer18 fixed on to one check 19 of the machine by screws 20. On the oppositecheek 21 there is fastened by means of further screws 20 a cover 22containing a lateral sealing shim 23 and its thrust springs 24.

In operation the scaling is ensured by the sealing shims 6 and 23 andthe radial segment, the sealing pressure being ensured by the springs 5,7 and 24.

The changing of worn parts is effected in respect of the lateral shim 23by dismounting the cover 22. In respect of the other parts, i.e. theshim 6 and the segment 4 mounted in the support 1 in a self-containedassembly, a standard exchange of these assemblies is made for assemblieswith new wear-prone parts kept in store.

For this purpose the knurled knob 28 is detached from the threaded rod25 and this latter is disengaged from the boss 29. This allows thedismounting of the component 10 after the nut 12 and the screw 15 havebeen removed. The removal of the washer 18 then allows the segmentholder assembly to be withdrawn, which can be gripped by the rod 12.

In order to reassemble a new segment holder assembly the fillet 17 isinserted into the corresponding slot 16 in the stator cavity. Thesegment 4 is previously kept sunk into its seating by means of plugs orbeads 26 (FIG. 4) made of heat-destructible material such as wax whichdoes not leave any deleterious residues, so as to remain temporarilyclear of the line 27 bounding the space swept by the rotor 3. The body 1is then fitted by its corresponding slot 16 into the guide fillet l7 andsunk into the stator cavity. The fillet 17 left projecting beyond thecheek 19 is then withdrawn and the closure washer 18 is replaced withthe control means for adjusting the inclination. As soon as the assemblyundergoes a rise in temperature, thus melting the plug 26, the segment 4comes into contact with the rotor surface and a new setting adjustmentcan be undertaken.

A replacement of the complete assembly can likewise be efiected veryquickly after stoppage, by dismounting the screws 20, removing thecomplete assembly and putting into place a new assembly likewisecomprising the washer 18 and the adjustment members. In this case thepreceding procedure is no longer necessary but involves a stoppage ofthe machine for a very short time. While the segment holder assembly 1pivots during the adjustments for setting the inclination, the shims 6and 23, which are of the same diameter as the outer diameter of thesegment holder and fit into the same bore of the cheeks 19 and 21,remain fixed because they are held in rotation by the ends of thelateral segments 30 (FIGS. 3 and 4) which are fitted into the shims. Theshims 6 and 23 comprise a concentric circular channel 31 which enablesthem to interlock against the portion 32 of the body 1 which forms theconnection between the end seating collar and the truncated cylindricalzone forming the radial segment holder.

What is claimed is z 1. Sealing device for rotary piston machines of thetype having radial segments adjusted in a support within the stator,comprising as a detachable unit a segment holder support, a lateral shimand a radial segment, said segment holder support fitting in acylindrically walled cavity open along axial direction of the rotarypiston machine and having an axial slot in which the radial segment isdisposed, a part of said holder support extending outside of te statorto form a sealing collar for a screwed-in cover, said lateral shimhaving approximately the same diameter as said collar and thecylindrically walled cavity for said holder support, and being disposedbetween said screwed-in cover and the part of the segment holder fittedin the stator, and first resilient spring means between said segmentholder and said radial segment, and second resilient spring meansbetween said cover and the lateral shim to press the radial segment andthe lateral shim against the piston, in sealing connection.

2. A device as claimed in claim 1 in which temporary guide means areprovided to ensure the insertion of the support into its cavity.

3. A device as claimed in claim 2, in which the cylindrical portion inthe stator comprises a longitudinal dovetailed slot, with which anequivalent slot in the segment holder support registers in the meanposition, a fillet whose section is adapted to the profile of the twounited slots ensuring the guiding of said support during its insertioninto the cavity.

4. A device as claimed in claim 1, with means to hold said radialsegment in its seating during its mounting on the machine in operationcomprising a shearing bead or plug made of heat-destructible material.

5. A device as claimed in claim 4, in which said shearing bead or plugis made of wax and is inserted in drilled holes having their axis on thelateral surface of contact of the segment with the corresponding surfaceof its seating in the support, its length being proportional to theforce of resistance to sheering to be provided.

6. A device as claimed in claim 1, in which the segment holder assemblycomprises means for adjusting the angular setting of the segment holderassembly having the radial segment therein and means for locking theinclination of the segment holder assembly.

7. A device as claimed in claim 6, in which the adjusting means of theangular setting are detachably 9. A device as claimed in claim 1, inwhich the lateral sealing shim is of approximately the same diameter asthe segment holder and contains a concentric circular channel forinterlocking with a portion of said segment holder assembly.

10. A device as claimed in claim 6, in which the inclination lockingmeans are mounted on the intermediate connecting component and thebearing washer.

, l l l

1. Sealing device for rotary piston machines of the type having radialsegments adjusted in a support within the stator, comprising as adetachable unit a segment holder support, a lateral shim and a radialsegment, said segment holder support fitting in a cylindrically walledcavity open along axial direction of the rotary piston machine andhaving an axial slot in which the radial segment is disposed, a part ofsaid holder support extending outside of te stator to form a sealingcollar for a screwed-in cover, said lateral shim having approximatelythe same diameter as said collar and the cylindrically walled cavity forsaid holder support, and being disposed between said screwed-in coverand the part of the segment holder fitted in the stator, and firstresilient spring means between said segment holder and said radialsegment, and second resilient spring means between said cover and thelateral shim to press the radial segment and the lateral shim againstthe piston, in sealing connection.
 2. A device as claimed in claim 1 inwhich temporary guide means are provided to ensure the insertion of thesupport into its cavity.
 3. A device as claimed in claim 2, in which thecylindrical portion in the stator comprises a longitudinal dovetailedslot, with which an equivalent slot in the segment holder supportregisters in the mean position, a fillet whose section is adapted to theprofile of the two united slots ensuring the guiding of said supportduring its insertion into the cavity.
 4. A device as claimed in claim 1,with means to hold said radial segment in its seating during itsmounting on the machine in operation comprising a shearing bead or plugmade of heat-destructible material.
 5. A device as claimed in claim 4,in which said shearing bead or plug is made of wax and is inserted indrilled holes having their axis on the lateral surface of contact of thesegment with the corresponding surface of its seating in the support,its length being proportional to the force of resistance to sheering tobe provided.
 6. A device as claimed in claim 1, in which the segmentholder assembly comprises means for adjusting the angular setting of thesegment holder assembly having the radial segment therein and means forlocking the inclination of the segment holder assembly.
 7. A device asclaimed in claim 6, in which the adjusting means of the angular settingare detachably mounted on an outer bearing washer positioned over saidscrewed-in cover.
 8. A device as claimed in claim 7, in which thecontrol of the angular setting adjustment is effected by means of ascrew held in translation by a swivelling boss firmly attached to theouter bearing washer, said screw driving rotarily the segment holderassembly by means of an additional swivelling boss attached to anintermediate connecting component which is in engagement with thesegment holder assembly.
 9. A device as claimed in claim 1, in which thelateral sealing shim is of approximately the same diameter as thesegment holder and contains a concentric circular channel forinterlocking with a portion of said segment holder assembly.
 10. Adevice as claimed in claim 6, in which the inclination locking means aremounted on the intermediate connecting component and the bearing washer.